RESUMO
BACKGROUND: Otitis media (OM) constitutes an important public health problem in the Inuit population of Nunavik, Northern Quebec. One of the objectives of the childhood pneumococcal vaccination program is to reduce OM burden. The program was implemented in 2002, and 7-, 10-, and 13-valent conjugate vaccines were used sequentially, with doses offered at 2, 4, 6 and 12-18â¯months, respectively. OBJECTIVE: To assess the prevalence of middle ear abnormalities at age 5â¯years in relation with exposure to different pneumococcal conjugate vaccines. METHODS: Immunization cards and audiology screening tests at age 5â¯years of children born in 1994-2010 were reviewed. Children were classified according to the vaccine schedule recommended for their birth cohort or to the vaccines they actually received. Log-linked binomial regression models were used to assess the relative abnormalities risk according to different vaccination schedules. RESULTS: Among 3517 children with complete documentation, the prevalences of minor and major abnormalities were 29% and 18%, respectively. Minor abnormalities frequency was higher in unvaccinated children (34%) and lower in children vaccinated with PCV7 (22%), PCV7â¯+â¯PCV10 (17%), PCV10 (15%) and PCV10â¯+â¯PCV13 (18%). No substantial differences among vaccine schedules were observed for major abnormalities. CONCLUSIONS: Pneumococcal conjugate vaccination was associated with a decreased frequency of middle ear abnormalities although no effect was seen for major abnormalities which may be trigger by OM with early onset. Clinicaltrials.gov registration number: NCT01694329.
